I offer this in the spirit of learning mindfulness, not as an attack. The fact that 10 people agree upon something and derive feelings of unity and harmony from their agreement does not mean that what they agree upon is objectively correct. So long as they do not or cannot test the subject of their agreement their harmony is a product of assumption. However, those good feelings may be more important to them than discovering if the agreement is in fact based on reality, in which case it is preferable to maintain the joint illusion and remain happy.

I test everything I can since I am deeply familiar with the human tendency to cling to that which makes them feel good about what they hold onto. Spirituality is the safest ground of all since there is no test which we can all agree to, At least when someone designs a 1 winged plane we can all watch the crash.
'A scholar was being rowed across a river and by way of conversation asked the boatman," my dear chap, have you ever learnt to read?" The boatman replied, "no." To which the scholar, "well then you have wasted half your life." Sometime later a storm began and the boatman asked, have you ever learnt to swim?" and the scholar shook his head. the boatman then said, "well you just lost all yours".